SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '984a441ad6cb1e157a669d5f857c941f7fa553ea82fc982494dab3334a7c89c1' 
  AND token = 'rpUJx35gC06sQAXfJW6+rUgLoW3Rv3VYtPGnmJul2Hc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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