SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d928b2bead82d444cdd574086f8c2adba556d9071d15e4881909f37d774323c' 
  AND token = 'poaaSDjKRHeXSNsRX5rx6+EDv8lj+OqFTxwln4iAsGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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