SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7a4d5e7d9471ad292417713557f33a25e668f0f17d9e3c13c5a22983635c2343' 
  AND token = 'z/kRpfiQqW+RyP9tajrMwtVGA6VQXPcD7GwYWjtk4Zo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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