SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7430189287250be40085126c9dbea48943fc912c90f45f722e61c2a98ce4d072' 
  AND token = 's4UbeaVDOvl5w1dzB9VVLwKsUnCBfGQmm4uC6DvfS6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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