SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2b95388fe5e6a5727b4145d9873ddde4d1a804d9b6c709bbf5aab2d153ba5d9' 
  AND token = 'Fp8j4/3DcczWWDnBQOuIJ2nh7wsM4lEpVBLFLQmo0Oo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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