SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f137e0e0b271c4c2e9bdd13369f083233877b29fa75ab77577b0057b80c204fc' 
  AND token = 'v4Shkt023hNFbtklTnCnL1imRaP1x1Shne0VkV9IHrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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