SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '215af0879ee1c23a59ac551e934e3def4566e01c1f3afe12ea09ee5df1f583b2' 
  AND token = 'V5sMVyt2a/TMTGEREqrVnWoq9it8XvBPyUEHRfHNWTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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