SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '040ba172d6cfe66948b264cd74d3354c1b433d6e57ef9f288c46cdac2327589a' 
  AND token = 'f62PpA2cAtpy0P6ko0tFkzi7kXrBwpjqUfC3+8RBTKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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