SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b22714b22c6a65fb2187f7363863bb1639f7ce44e9670d3c44cafaa2bd737310' 
  AND token = 'Rb5ZgxjGko+3r4d01dPpqughQlReUfyMkzbJtvmCpwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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