SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4c5b239e2105949988ef9469adda39ff34ca3ba635fa0e8f314f123ffbd7247' 
  AND token = 'BBqgFlGAHIsM/2A+ANw3YHYe8Cz2fQ5GooeLRo/lVqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}