SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a520c381208fac2aa822094f54898294ea1f53b5e917b9ce5da91e38025dbff' 
  AND token = 'dz6nah4HkouO/vNF4gjecGoi6OYLTWXAJSTcY5JOW/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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