SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c6793b4b0c1560408535645072d738fa708905455d542d43d6bd50e83164ca7' 
  AND token = 'JcmJKKfYMP7DMp/uS5/1eLpfn0jXANfHgbg4Pr+G7oE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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