SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98d5236ad4c1c4d46a2c6dbe694e70e1d35f90ba4129bf8cfac41fc887d53246' 
  AND token = 'Gda+qxxKpq2rGn0UtU1XguR/ZApI35Il0+8ovRGB0Y0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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