SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '08d285e099d005f1e985b54cd9924037f2629a547852a1b870d0fed69dfadf0f' 
  AND token = 'cAh2aeth+uJuSpQM4tYlOT+2Cprt4PkB/BAcN39TqCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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