SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22bef77af03f855efa16c12abb4ca25aef88ecc8ec239549691e8a121a22c572' 
  AND token = 'pmLTxCyhPkFH1ziRz41ncoUNBoYgStEYxpzSnZXXEU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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