SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '34be09d57eacf4773f6fdb9001125c3253cf22afc904b6d22a2c7fa8c73888f6' 
  AND token = '32cAB/xGrrtTS8u3CFdTydY7Ji44srWcGsHdCtpz7Cc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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