SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d9c79d2c6b01694fd8656c10935fe310cc4c808ec19ce8bf9b6b1abca668cb1' 
  AND token = 'VOFL7fmTRi3k+iq8Qek3dQLwvnI/8kplLovPMUx3qtY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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