SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f953edefa6c5f55b6b4aa776011a455f22bc1028f2b348a3ffba96a8683c0afb' 
  AND token = 'u3eljuHzjd7E5hkzq1VM6ppVFQrTDq5lLDUJJtayuwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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