SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cae23155291e39752d3268eca49f2c1f9c438e15a57117f6d7baddb155fa442b' 
  AND token = 'PouuyjDSCHw507GOxW8Ay9K44+rAOC/Vq6NGbbqryzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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