SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e08de7bb627695ec94b496761b7c74eba3f0f4a91bbcd6702c053dc06406710a' 
  AND token = '+jUx6diHlZypWDBLcimI/Ubme2gm9HLkK4k3thmm9iA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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