SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bf28b4aafbe31438af67049704f30ee98e90507c510bb94a17d802a419d1a57' 
  AND token = 'P81BSlFDrQEnpC06BoapJjdFZi/akRPKazMX7RbxSSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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