SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b7cd420176942d23a1132c925a7216f38e978f9a7f91f8a18c514c0ddaa233ad' 
  AND token = '8daX8s/3YMkC62lOMw15MuK27V2EGT7/5sPtSxaZ5DY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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