SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0ac25231cc9354370752e6138ebc39c7ae68a69369bc32dac58ee0dd8f30daab' 
  AND token = 'mksSYVPCUv6sphF/jGZ53Vt4bfVY/MKOtGxhhT99t9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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