SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aece32071eab826bb7b2c999e3168b067a36c60442f446886745a1b68888ffa7' 
  AND token = 'FjPMpvSm5CjezghoFsJoc2R+zZWHpOQtXyQTSdevIB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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