SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd0948a1189307b65407107f05315cfcd7aa0db2faccfc436408367e31c0867be' 
  AND token = '8sj3AhAOJ40NtzO+DBr7H7Bj/ZYWyd3vAWDSapPRhDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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