SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2100d93ec909f08387fd86b0323e562587ebca0913c7a471aca379b31ca487ca' 
  AND token = 'Ye9lqrGWYwLYEKrYMJ8+l7qkXGHS/76f3PKTl0+E6fY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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