SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f981f31b2c8831ea0959e4b8e1b0df8501298d314d84c3913efb2f3bc4e4192' 
  AND token = '3DG/ZkBx+9I47NvVpc/0snhLsAzthDLQZyi07tReEYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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