SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4dd41798b36b10a627b674eb327da941949acd5916756ccb7113c6d73872369' 
  AND token = 'eC3QRUjJoX2tBzRbb23xd+SPn7BJhuIPgORTJZ1oFQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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