SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ccf54842ed4a23261e4726bfe2952823563c842dae0f3c58f5df61182469c62' 
  AND token = 'OyuLcarPz6U4jB5hc73dewBzzobRLyo7RLYxFctPQLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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