SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6e0198972caf0cfc1f281a6a2f6e3384f791593d045e79882197f62b0f7a880b' 
  AND token = 'IRR1+jVoeEg+Y7MSUPTyPC2eXDPFGbpCJwxVobejPbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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