SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2d1ba756c715869b373c11401bfa80dbb1f9e510ef0aec119bcaee2a91b47cd3' 
  AND token = 'BArV2oqclD3XcM0DTg01ucALL+Y0lxzfsKEPqnXTSBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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