SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4be02d7b80259c4bcadfeebc02ef43f5154aa245e5e4f4f29be3213418d3f45' 
  AND token = 'iWYCJ7ygf8UHnCJUyeRTU72LlfqQDMcGR2QfPEZXWgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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