SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ffbc4aa9d9583d0793907c653965924f784117e21d4b17f1119f4ac67036681' 
  AND token = 'Msi47zrLsb3/anrpuZ+gRQKcb5meiF0i7H8xZAO3p0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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