SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c18ab302897486777d3c91c20519b182cb0a745d5528f77dd5d588ac9d09511a' 
  AND token = 'ixtqpMPJYPAibrX4UPyPq9I9NiNJ+cGoQP1m2+BvVKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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