SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19f92e2f6b2587fac0d8f061ef6246382b5064315530978f7fb953676e206429' 
  AND token = '0zzpYEgMXCcp/bnDGkdtGbzgZTvbDH+fXjhfJGFW0zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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