SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92a7a452c09075133be56c591b6540251551e676e1aa9809571eeed64860073a' 
  AND token = 'TYCWsYSZ5UHmR59o1F4cvWy7pF5oxhNJGMK/ELchV3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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