SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3d41a380a492e0ae7cfd14772a67368471d1ec67927f796f2ea813225e784c5' 
  AND token = 'YGtFT9tn+vy/i/NylLneqpHsewZ2DBQTkJzzIKy4jwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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