Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d46e5a7442ed8da3cff3ff66c90cbefb89d0e1040b0ed411fce561e1df8cca0' 
  AND token = 'gZ4tMU8T+HWSdM+bEyJQf2OoMeTHRbQFFwZ9nTH/VRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}