SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90565ec9fbefdbb70ccf52bc73e81d183cd973d525bf21444c23d5eab87b5264' 
  AND token = 'wN31vzF+CHXvoauOUmbQPT7D7r+2dn8yKJvPtBOBiYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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