SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f38c43d3d2242ad437b316c00033a462dba5f0b424fd37aebc1bdf958db08f25' 
  AND token = 'x4fv9apWZqXpFehT5od0veM3+gYywOOR5MD32VdD1pI=' 
  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"
    }
  }
}