SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '551a8c9532e084abb8fd325ffdacc3dd5ee3b6412c18836cc5426ee8cd987f3e' 
  AND token = 'c8aNW9CWsbBNRaF5sqUyMelfw2MjI44FTXA2Pl4Vvic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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