SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b4190a53ccc74c52239dfd1af065af2c26e846d5832e81b685d06d00897f065' 
  AND token = 'NNP1mMVRrJmAU4pkOrPF+AMB4tTYV5E9+hgGbKCajlc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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