SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8445ba9834d457ece04de655a7a9cf91a2728df0843111b4dbcebc9f43c3f567' 
  AND token = 's1mxLLZGVFDmisjXv2ZeXhiYM8k6sqV8xmIpzhB9sNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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