SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dd216c87dc9feb4182f5e4406c22d6180ceccefaad7af997945a3e87aae8c5a' 
  AND token = 'q4jEGhbCWdxI8xIRFDCuDvOkKR7eTtzjbiummb/Oixg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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