SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7af34bb41627c0313fe998aea0407c5100d550653f6d3e05b25aa54dec1add0' 
  AND token = '9smbrrIdZ1NQGlrgYtjUTedzoffrcgmak2crBp26XPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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