SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe2b8b18460f8102ce93c6aac491898218d61d3bbb7b0ff20ec3d650392dd7aa' 
  AND token = 'EhDvh/NdxV/Ea+G5bVx/CtQz7W/8MdFlVKSb5g/ZzjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}