SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c7a12c1f82bb75831576b5bd6b0f3e9e60bb0c699c3aea33bab2088817d47b4e' 
  AND token = 'pCIXBqsrTAtfgnpakMzi2rU5zeVnqIDgXDwadh2NyGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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