SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbb9251c9fa81219b31d78db82922c43e209141e4f61ca63da0ccdd3318a1dc2' 
  AND token = 'Icoj8m6cRazwiAwpAM+R2x/W84ZyaUk7aapCFg83b4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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