SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfaa3e8b7b20b99617c199978c24f90321c47912b9cb4290cb12987b5249906b' 
  AND token = 'FSndrL2c6luWqDtCNZTGYeLuFEesSos+uC10CPZFIfc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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