SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '948e5ac7fb47225fb5692deb3511371ae25ba04ba1ff8495780407e6e3bbffb8' 
  AND token = 'hCnMk9Uv76/tX+TQ8/kARyhs0pISGlQrjMuQKC1/F58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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