SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1266cd307bac75f1f34e3a1e2949d3342e7becd204b7b00e16f2f54112ece35a' 
  AND token = 'nj+lV8FppwcUgMLjqFl+gEbAtx/6KZW6mYh7BlgxcYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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